CHULA VISTA  A band of brazen houseflies flew into an Olympic Training Center clubroom last week, drawing the ire of a sitting Maya Theuer.

Clearly, they didn’t know with whom they were messing.

She traced the buzzing insects with a steel-colored stare usually saved for soccer forwards slick enough to test the Bishop’s School defense — right before Theuer, a senior co-captain, makes a sudden, decisive move to squish the intrusion like a kitchen fly swatter.

Theuer relishes being a team’s last line of defense, and her knack brought her to Chula Vista’s state-of-the-art complex where she trained for nine days as part of the United States 18-and-under women’s national team.

Theuer was one of two San Diego-area players in camp, alongside Torrey Pines High senior Laura Liedle. The San Diego Surf club teammates, respectively ranked the Class of 2012’s No. 6 and 3 recruits by

As much for her athleticism and vocal leadership, Theuer is regarded for her competitive streak.

Case in point: June 18, 2008.

The San Diego Surf 14-and-under white team faced a team based in Folsom at the Far West League Regional Championships in Hawaii.

The game took its last breath. The Surf trailed 2-1 and would be eliminated with a loss. They had a desperation corner kick and pulled their goalie to stack the box.

In came the cross, but the ball popped out of Surf traffic. An opposing forward took possession and sprinted toward an empty net, as Theuer closed from behind.

“I didn’t want to lose 3-1, so I kind of tackled her,” Theuer, 18, said with a laugh. “I ended up getting a red card, but they didn’t score.

“Nitty-gritty. I like the hard tackles. I won’t hesitate to — I don’t want to say hurt someone, but get the ball, regardless of who’s in the way.”

High-level athletics and sacrifice typically go hand-in-hand.

She missed a week of school and two Bishop’s games while at the training center. She also missed Bishop’s loss to Coronado in the San Diego Section championship last season for another invitational in Arizona.

Camps allow Theuer to stack herself up against the nation’s best, a checkpoint as she targets a spot on the 2014 FIFA U-20 Women’s World Cup team.

A more immediate goal is a section title this season and another deep run in the state regional tournament; Bishop’s made it to the semifinals last year before losing to Westlake Village Oaks Christian, the eventual Southern California champion.

There is the rough-and-tough soccer side to Theuer, molded from early years of playing soccer in the park against her older brother.

“The physical contact knocks you back, takes your breath away,” Bishop’s coach Brian Quinn said. “She doesn’t do it, but she has it in her arsenal ... It’s like a free safety hitting a running back. She’d be the winner.”

Away from the pitch, the La Jolla resident walks around the school campus, yet to find an upperclassman or underclassmen to whom she won’t say hello, she says.